The reason the domain is Eukarya, is
it's more complex and includes genetic material that is organized into a
membrane bound nucleus.
The kingdom Animalia is described as
multi-cellular organisms that can respond to its environment.
Being in the phylum Cnidaria tells us it is
a primitive animal that has a single body cavity. This cavity
doubles as its stomach, lungs, intestine, and circulatory system.
The class Anthozoa is for sea anemones and
hard and soft corals because they are attached to firm objects.
Then you can narrow down the order Actiniaria,
which is the order for all sea anemones.
The family Stichodactylidae includes two
genus, Heteractis and Stichodactyla, both of which host
anemonefish.
The genus Heteractis is known for
it's stinging tentacles which look as though they have bubbles on the
ends.